Pitman connection for harvesting-machines.



J. H. DOWNING.

PITMAN CONNECTION FOR HARVBSTING MACHINES.

APPLICATION FILED H1315, 1911.

1,029,533, Patented June 11,1912.

I unir mwu/ c LUMBIA PLANMRAFH c0..wASH|NuToN D c rs r OFFICE JOHN I-I.DONING;y OF STILLWATER, MINNESOTA, ASSIGNOR TO THE STATE OF MINNESOTA.

PITMAN CONNECTION FOR HARVESTING-MACI-IIN ES.

To all whom 'it may concern:

Be it known that I, Jol-IN H. DowNING, a subject of the King of England,now residing at Stillwater, in the county of Vashington and State ofMinnesota, have invented certain new and useful Improvements in PitmanConnections for Harvesting-Machines, of which the following is a full,clear, and exact specification.

The invention relates to pitmen connections for harvesting machines, andparticularly to the connection at the iy-wheel or crank wheel end of thepitman.

The object of the invention is to provide an improved pitman connectionfor connecting the fly-wheel end of a harvester or mower pitman to thecrank pin, which shall be simple in construction, efficient inoperation, and provided with improved means for receiving andindefinitely retaining a supply of lubricant and gradually supplying thesame to the frictional surfaces between the crank pin and the bearingportions of the connection.

To the attainment of these ends and the accomplishment of certain othernew and useful objects which will subsequently appear, the inventionconsists in the features of novelty illustrated in the drawings forminga part of this specification, set forth in the subjoined specification,and linally pointed our more specifically in the appended claims. y

In the said drawings-Figure 1 is a plan view of the improved pitmanconnection, showing the same in position on the crank pin or fly-wheel,portions of both pitman and fly-wheel being broken away. Fig. 2 is aview in elevation of a portion of the pitman adjacent the fiy-wheel, theparts of the connection being in section in order to disclose theconstruction. Fig. 3 is an enlarged plan view, all the parts being shownin section with the exception of the crank pin.

It will be apparent Ithat the improved pitman connection herein shown,described and claimed is capable of use in any desired form of pitmenfor harvesting machines, that is, pitmen formed either of metal or ofwood with metallic connections at the knife and fly-wheel or crank pinends. In the present embodiment of the invention it is shown applied toa pitman of the wood type, the wood body thereof being indicated by thereference character 10.

Specification of Letters Patent.

Application led February 25, 1911.

Patented June 11, 1912.

Serial No. 610,710.

11 indicates the fly-wheel of the harvesting or mowing machine, and 12the crankpin carried thereby eccentric to the pivotal shaft on which thefly-wheel is concentrically mounted, such shaft not being illustrated inthe drawings as it forms no part of the invention. The crank-pin 12 maybe secured to the fly-wheel in any desired manner as by forcing thereduced portion 13 thereof into a hole in the fly-wheel and securing thesame in position either by upsetting the reduced extremity of the pin orin any other desirable or well known manner. The bearing portion of thecrank pin 12 being larger than the reduced portion 13 which enters theeccentric hole in the flywheel, a shoulder is formed on the crank pin,as indicated at 14, abutting against the fly-wheel when the crank-pin isin position. The outer extremity of the crankpin .l2 is reduced andthreaded in order to take the retaining nut 16.

17 is a bushing being adapted to ft closely around the cylindricalbearing portion of the crank-pin 12, and in length extending from end toend of the uniform cylindrical portion of the crank-pin, the same beingthe body thereof which extends from the abutment 14 to the outerlextremity of the bearing portion of the pin or flush with the reducedand threaded portion thereof. The inner or fly-wheel end of the bushing17 is provided with the enlarged circumferential portion 17, one side ofwhich forms an enlarged bearing surface against that portion ofthefly-wheel immediately surrounding the crank pin, thereby increasing thebearing surface and consequently the life of the bushing. The bushing 17may be formed of any suitable material adapted to be used for bushingsor bearings. It is preferred that it be formed of a different metal fromthat of the crank-pin, and since the crank-pin is usually of steel it ispreferred that the bushing 17 be formed of brass or suitable alloy.

It has been quite common to form the entire pitman connection exclusiveof the straps 18 of brass or other suitable alloy for bearings, but thisis objectionable because such materials are usually more expensive thangray iron, for example. It is also desirable that the bearing'memberproper exclusive of bushing be of a metal having sufficient consistencyto withstand the pounding and various forms ofthrusts due to theconnection of the bearing with the retaining straps 18, which are shownin the illustrations riveted as indicated at 18b to the wood pitman 10and provided with the cooperating conical lugs or extensions 18aengaging cooperating conical recesses in the bearing block proper. Thislast mentioned member is indicated by the reference character 19 and ispreferably formed of cast iron and so may be cheaply produced in theirregular form shown and at the same time have the quality of resistingthe pounding and thrusts imposed thereon Withoutbeing seriously worn ordistorted. The bearing block 19 extends from the outer edge of theenlarged portion 17aN of the bushing to the extreme outerrend of thebushing itself, where it terminates iiush with the bushing and with theouter extremity of the bearing surface of the crank-pin, thus making itpossible to secure both bushing and the cast bearing 19 in their normalworking positions by means of the washer 20, which is secured over thereduced threaded portion 15 of the crank-pin by the nut 16. x

About midway of the extremities of the bearing block 19 acircumferential housing 19a is formed, which preferably has suiicientdimensions to Secure on the 'interior thereof a circumferential cavityor oil pocket 19b bounded by the housing 19a and the bushing 17. Thiscircumferential cavity or oil pocket 19b is therefore closed to retain aconsiderable quantity of oil, being provided only with the filling duct19C, which extends through the boss 19d on the top of the bearing blockfrom the exterior and opens into the cavity or oil pocket 19h, beingadapted to be closed by the removable threaded plug 21 adapted tocoperate with the threaded upper end of the filling duct 19C.

The bushing 17 is provided with one or more feed vents to allow the oilto reach the bearing surface 12 of the crank pin. These feed vents arepreferably two in number and located as shown most clearly in Figs. 2and 3, being indicated by the reference characters 22, and situated atthe sides of the circumferential portion of the crank-pin and midwaybetween the top and bottom thereof. This construction, it will be seen,permits of a considerable quantity of oil, about one-half of thecapacity of the circumferential oil cavity 19h, to be normally heldwithin the circumferential cavity without any avenue of escape until theoil is splashed above the level of the vents 22 by the movement of thepitman. In pitman connections as heretofore constructed this bearing onthe crank-pin has been the source of much trouble because of thedifficulty of properly lubricating the same. There has generally been noprovision made for retaining more than a small quantity of oil in thepassages leading to t-he bearing, and when the Vmachine is in operationthis small quantity of oil is soon thrown from the bearing by reason ofthe centrifugal force of the bearing since the crank-pin 12 is eccentricto the axis of rotation of the flywheel, so that while the operator ofthe machine may frequently lubricate this bearing the oil or otherlubricant would not be retained for but a very short time and thebearing would run for the greater part of any interval almost entirelywithout any lubricant whatever, causing the bearing to heat and wear.

The bushing immediately surrounding the crank-pin has heretofore beenmade of brass or other alloy relatively expensive, and because of thedifficulty of lubricating the parts these bushings have worn out veryrapidly, entailing one of the greatest expenses in keeping a mowing orharvesting machine in repair. By reason of the closed circumferentialoil cavity 19b by my improved construction it is possible to retain oilin this bearing for a considerable time, and if desirable the cavity maybe partially filled with some suitable retaining fiber, as wool and thelike, commonly used to assist in the retention of lubricants inbearings, although I do not illustrate such ber in the drawings as itsuse is common and well known. However, with the use of my improvedbearing which is normally closed with the exception of the feeding vents22 leading to the bearing surface of the crank-pin, it is found that theuse of the fiber within the lubricating chamber is not necessary.

In the manufacture and assembly of the parts it is desirable that thebrass or alloy bushing 17 should be a close fit, preferably a drive fitin the bearing block 19. This insures a closure between the bushing andthe walls of t-he housing 19a and renders the circumferential cavity oroil pocket 19h proof against the leakage of oil.

In order that the invention might be fully understood the details of thepreferred embodiment thereof have been thus specifically described, butit is not desired to be limited to the exact details of constructionsince many modifications thereof may be made without departing from thepurpose and spirit of the invention.

What I claim is:

In a pitman connection for harvesting machines, the combination with acrank wheel and a pitman, of a crank pin secured to the said crank wheeleccentric to the axis of rotation thereof, there being a bearing surfaceformed on the said crank wheel circumferentially of the crank pinadjacent the inner end of the bearing surface thereof, a bearing securedto the pitman and sleeved over the crank pin, said bearing comprismg aninner bushing of material having suitable frictional qualities and beinguniformly cylindrical throughout the major portion of its length andhaving a flanged portion oi increased diameter at its extreme inner endwhereby a covered bearing surface of increased thickness is provided atits inner extremity to cooperate with the said bearing surface formed onthe crank wheel for taking end thrust on the bearing, and a bearingblock secured to the pitman and sleeved over the bushing, its innerextremity in contact with the shoulder formed by the increased diameterportion at the inner extremity of the bushing, its outer extremity beingflush with the outer extremity of the bushing, there being acircumferential cavity or oil pocket formed in the bearing crank pinsaid means extending beyond the ends of both bearing block and bushing.

In testimony whereof I have signed my name to this specification7 in thepresence of 30 two subscribing witnesses, on the 21st day of February A.D. 1911.

JOHN H. DOWNING. Witnesses:

H. W. DAVIS, S. D. PORTER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, I). C.

